1. Field of the Invention
The present invention relates to a technique for sharing and managing document data, particularly attached files to electronic mail (e-mail).
2. Description of the Related Art
Various types of document data management systems that include a client/server type application or a WWW (World Wide Web)-based application are used in recent years. In such a document management system, generally, personal computers (hereinafter referred to as PCs) handle electronic documents (hereinafter referred to as document data) by using a dedicated client application or a web browser. With the document management system, folders and documents are hierarchically managed, and the document management system is used to share the documents by granting users different access rights to the folders and documents.
Meanwhile, electronic mail (hereinafter referred to as e-mail) is an essential means for performing business operations, and is widely used as an information sharing means. E-mail is also used as a file sharing means by attaching a document file thereto. Also, WWW-based e-mail transmission/receipt systems (hereinafter referred to as web mail) are also widely used, and transmission and receipt of e-mail is possible even in an environment in which client software (hereinafter referred to as a mailer) cannot be used.
Generally, e-mail is stored in a data storage area secured for each e-mail address. In other words, e-mail is not designed to be shared with other users, and access rights are managed as data specific to each individual. Accordingly, in transmission and receipt of documents by e-mail, when editing operations of a single document are cooperatively performed, management of update history becomes cumbersome. Also, in order for a user added as a destination to reference a file attached to a past e-mail, it is necessary to resend the past e-mail when sending a reply.
For the purpose of addressing the problem described above, a technique has been proposed in Japanese Patent Laid-Open No. 2006-330899 (Patent Document 1) in which mutually related e-mails and attached files are extracted from an e-mail storage area, and a set of e-mails and a set of attached files are associated and stored.
However, according to the technique described in Patent Document 1, the sequence of e-mails and the file set (the set of attached files) are related and collectively stored in the storage area. Accordingly, there is a possibility that modification management of the files that have been saved in the storage area might become cumbersome. Also, when a shared folder is used as the storage area, there is a possibility that the stored e-mails and attached files might be referenced by users other than those the sender intended. In other words, there is a problem in that management of a modification history of attached files (version management) and setting of access rights cannot be performed appropriately.
The present invention provides a more preferable management technique for sharing document data attached to e-mail.